This study provides the first comprehensive investigation of the relationships between mistletoes Viscum album L. (Santalaceae) and Loranthus europaeus Jacq. (Loranthaceae) and avian species in Europe. Its aims were to: (1) document the diversity and richness of European bird species that use mistletoe for nesting and shelter; (2) determine the factors influencing nest site location in mistletoe by different bird species; and (3) assess the impact of anthropogenic factors on the mistletoe nesting site location and possible selection of mistletoe as nesting sites. Mistletoe is highlighted as both a keystone resource and a critical arboreal microhabitat for nesting and roosting, shaping local patterns of bird diversity and abundance in European ecosystems. We recorded 41 species of European breeding birds from 18 families nesting in mistletoe, with V. album supporting 39 species and L. europaeus hosting 7. Species richness of mistletoe-associated birds was higher in natural landscapes than in urban ones. Nevertheless, in urban environments, mistletoe remains an important nesting site, particularly for the Woodpigeon Columba palumbus, Fieldfare Turdus pilaris, Eurasian Collared Dove Streptopelia decaocto, Hooded Crow Corvus cornix, and Eurasian Magpie Pica pica. The impact of tree structure, mistletoe morphology, and environmental factors on nest site location in mistletoe clumps varied among bird species, reflecting strong species-specific preferences consistent with their general nesting behavior.
Long-term analyses of autumn bird migration in Central Eastern Europe remain scarce, particularly those based on standardised visual observations. We analysed 11 years of systematic counts (2012-2022) conducted by an experienced citizen scientist at a single site in northern Austria near the Czech border. The dataset comprises 5,411 quarter hours of observation from 6 a.m. to 12 a.m. between September and October, yielding 479,307 migrating individuals of 100 species. Migration intensity, measured as mean traffic rate (MTR), increased overall by 2% per year. This trend was driven by short-distance migrants (+3% annually), while long-distance migrants declined (-5% annually), with the steepest decreases in farmland species. Urban breeders showed moderate declines independent of migration strategy. Raptors increased markedly (+8% per year), primarily due to Common Buzzard Buteo buteo and Common Kestrel Falco tinnunculus. Phenological analysis revealed decreasing trends in September but increasing trends in October, indicating delayed departures for short-distance migrants and, unexpectedly, also for long-distance migrants, albeit at low abundance levels. Raptors showed consistent increases in both months. These findings demonstrate contrasting trends between migration strategies and breeding habitats, highlighting the role of different ecological pressures.
Parasites may influence ecological and evolutionary processes of their host species. Several studies have consistently shown that traits signaling individual quality are typically condition-dependent and that the presence of parasites negatively affects both an individual's condition and ornamentation. Here, we screened for multiple macro and microparasites and investigated whether infestation by lice impacts the condition, immune status, and ornamentation in Silver-beaked Tanagers Ramphocelus carbo. We found that 62.5% of individuals were parasitized, with feather lice being the most prevalent parasite. Blood parasites were scarce, with Plasmodium found in only 6.25% of individuals. No case of concomitant infection was recorded. We observed a positive association between body condition and total white blood cell count, whereas a negative association was found with the heterophil-to-lymphocyte ratio. Testes size and beak ornament size were not associated with condition. We also found a marginally non-significant tendency for plumage hue in adult males to be negatively associated with the number of lice. The low prevalence of blood parasites may be due to diminished vector abundance or high resistance and tolerance in this host population. While some of the traits we investigated were condition-dependent (such as immune status), our study revealed that parasite abundance did not significantly influence them. Nevertheless, the association between the number of lice and coloration may indicate that circulating carotenoids may play a vital role in immune response in redder males. These findings underscore the intricate interplay between parasites and avian characteristics. Future research should investigate the relationship of how circulating carotenoids may be used in coloration and their effects on immunological responses, with or without parasite infection.
Habitat selection is an important process studied in evolutionary ecology because of its effects on fitness. However, whether it is adaptive remains questionable, especially in disturbed habitats. I investigated nesting habitat To evaluate whether habitat selection was adaptive, I tested two alternative hypotheses using nest survival, which is strongly influenced by nest predation, as a proxy for fitness: 1. The potential prey site hypothesis, that suggests breeding pairs select habitat patches with more potential nest sites, thereby increasing the number of possible nest substrates predators must search, and reducing nest predation rates; 2. The total foliage hypothesis that suggests breeding pairs choose nest sites in habitat patches with dense vegetation to conceal nests and reduce predation risk. I first tested habitat choice and showed that the number of firs (Pseudotsuga menziesii and Abies concolor), locust Robinia neomexicana, and total woody stems were more abundant in nest patches than in random patches. The choice of nest patches with more total stems might suggest support for the total foliage hypothesis. On the other hand, the choice of nest patches with more firs might support the potential prey site hypothesis because they always built their nests in firs. I fit nest survival models to these habitat features and found that daily nest survival increased with the number of firs, supporting the potential prey site hypothesis. However, daily survival rate did not change with the number of total stems, rejecting the total foliage hypothesis. Ultimately, the choice of nest patches with more firs than random patches and the positive directional selection for numbers of firs suggest that habitat selection is adaptive in a fire disturbed area.
For cavity-nesting birds, forest structure may limit cavity availability, hence, these species have developed fine-tuned strategies for nest site selection. Anthropogenic habitat alteration as the invasion of exotic plant species has a globally negative influence on avian nest site availability. We evaluated the influence of the invasion of the exotic European Nettle Tree Celtis australis on the selection of nest boxes by the Southern House Wren Troglodytes musculus. This invasive tree usually forms forest patches and corridors characterized by a high density of trees and dense, intertwined canopies. During three breeding seasons (October 2022 to January 2025), we installed and monitored 60 nest boxes in a forested area heavily invaded with C. australis. The Southern House Wren occupied 38.3% of our nest boxes. Using logistic regression models, we found that the probability of occupancy was significantly lower in areas with higher number of trees surrounding the nest box. We attribute this phenomenon to less favorable microclimatic conditions (reduced ventilation and sunlight) associated with the higher foliage cover of C. australis. Our results indicated that C. australis invasion reduces nest box occupancy by the Southern House Wren. We encourage local authorities to increase their efforts to prevent the spread of this exotic tree in the native forests of central-eastern Argentina to ensure suitable breeding sites for the Southern House Wren, and by extension, other secondary cavity nesters.
Changing vegetation and animal communities in the subarctic from a warming climate may influence behaviour and nest success of breeding shorebirds. Nest site characteristics and antipredator defense behaviour in two cryptic shorebirds, Stilt Sandpipers Calidris himantopus and Short-billed Dowitchers Limnodromus griseus, are known only by qualitative descriptions. Our objective was to determine if Short-billed Dowitchers breeding at the northern edge of their range and Stilt Sandpipers breeding at the southern edge of their range differ in nest site characteristics, and if, as a result, they employ different defense strategies to minimize detection during incubation. We measured vegetation and the extent of concealment at nest sites of both species in fens near Churchill, Manitoba, Canada, and scored behavioural responses to human intruders during regular nest visits. Water depth and vegetation height within 1 m2 of Shortbilled Dowitcher nests were significantly higher than those around Stilt Sandpiper nests but there was no difference in substrate types at or around the nest. Concealment was significantly greater at nests of Short-billed Dowitcher than Stilt Sandpiper. For nests found before hatch, 85% for Short-billed Dowitcher and 57% for Stilt Sandpiper were successful. During 27% of nest visits for Stilt Sandpipers and 5% for Short-billed Dowitchers, eggs were unattended upon our arrival at the nest and no incubating birds were present in the area. While both species exhibited a range of defense behaviours, Short-billed Dowitchers flushed nearly underfoot after disturbance from an observer and engaged in significantly more aggressive defense behaviours such as distraction displays, whereas Stilt Sandpipers typically flushed from nests or departed before the arrival of observers. These differences highlight the importance of considering nuanced behaviors in apparent response to the local environment in the context of ongoing environmental changes in the subarctic.
Long-term monitoring is essential to address ongoing biodiversity loss. This study provides a comprehensive summary of the population trends of common breeding birds in Poland based on 25 years of data (2000-2024) from Common Breeding Bird Survey (CBBS). The dataset comprises 2.3 million observations of birds from 29,000 field surveys. Population trends were calculated for 124 bird species using generalized estimating equation models (GEE), analysed for two time periods: the whole study period (2000-2024) and the most recent 12 years (2013-2024). Trends varied widely among species, ranging from an 82% decline to a 579% increase, indicating that in extreme cases populations changed by up to factor of six over 25 years. Over the whole study period increases were more frequent than declines, however, in the last 12 years we found a shift towards declines. Multi-species indicators reflected contrasting habitat-specific patterns, with a 20.4% decline in the Farmland Bird Index and a 30.8% increase in the Forest Bird Index. These patterns were confirmed by trait-based analyses, which revealed that the most negative trends were recorded for farmland and wetland birds (the latter did not differ significantly from farmland species), while increases were found for woodland birds. Population changes were also linked to migration strategy, with the strongest declines observed among long-distance migrants. There was also a significant positive correlation between trends and body mass, as well as between trends and temperature preference, indicating that large-bodied and warm-dwelling species had more positive population dynamics. The optimal model explained 25% of the variation in long-term species trends, suggesting that additional drivers likely contributed to observed population changes. Overall, these results revealed substantial variability in population trends of common birds in Poland and highlighted the importance of continued long-term monitoring for understanding biodiversity change.
Long-term studies provide solid frameworks for addressing key questions in ecology and conservation. First, they allow collecting high amounts of data necessary to assess data-hungry hypotheses. Second, long-term studies allow testing hypotheses that require long time series. Third, they serve as sentinel systems to investigate the effects of sudden environmental changes (e.g., wildfires, floodings, severe droughts). Using the experience on a long-term study (2000-present) of Middle Spotted Woodpeckers Dendrocoptes medius in NW Spain, I identify and propose some approaches for addressing a set of key questions. Long-term studies are essential to investigate lifetime fitness performance of floating adults, which strongly influence population persistence of woodpeckers and many other organisms. A second data-hungry question is related to the factors that influence the use of habitat patches as stepping stones for dispersing juveniles and floaters. Long-term time series are also necessary to investigate population persistence under climate and habitat changes. Moreover, long-term data on woodpecker reproduction and cavity occupancy by secondary cavity users will help understanding the role of woodpeckers as indicators and keystone ecosystem engineers, and will unravel the mechanisms underlying nest-site selection in primary cavity nesters. Finally, woodpeckers habitat specialization provides a suitable framework to investigate the drivers of foraging habitat quality in birds. Despite the relevance of long-term woodpecker studies for the generation of robust knowledge, most funding programmes do not promote, or even penalize, studies on these species because they require long periods. This issue biases our knowledge towards model species and systems comparatively easy to study in short periods.
Woodpeckers represent a frequent component of mixed-species flocks in subtropical forests but have received less attention in mixed flock research than Passeriformes and other bird taxa. To understand when and how woodpeckers join this type of association and their role within them, we surveyed mixed flocks for 388hs over three years in Argentina's Yungas foothill forest. We studied the association frequency and foraging behavior inside and outside mixed flocks of the four woodpecker species present in the study area: Cream-backed Woodpecker Campephilus leucopogon, Golden-olive Woodpecker Colaptes rubiginosus, Dot-fronted Woodpecker Veniliornis frontalis, and White-barred Piculet Picumnus cirratus. Woodpeckers were present in 26% of the 206 recorded mixed flocks, with a higher frequency during dry seasons. They joined mixed flocks with twice as many species as the average flock in the area and shared the flock with other non-woodpecker bark-forager species in 88% of cases. The largest species, Cream-backed Woodpecker, joined flocks less often than smaller species but frequently participated in flocks composed mainly of other large-sized bird species. We recorded the foraging behavior of 52 woodpecker individuals for durations ranging from 11 to 449 seconds: 24 within mixed flocks and 28 outside. Some woodpecker species were found to mimic other bark-forager species' foraging sites in an exact manner. Medium-sized species foraged higher when inside mixed flocks, whereas the largest and smallest species did not alter their foraging height. Only the smallest species, White-barred Piculet, increased its foraging efficiency within mixed flocks and was recorded as a leader in understory flocks. Further insights are needed into the disadvantages and/or benefits of woodpecker species joining mixed flocks. However, our results indicate that woodpecker participation in mixed-species flocks is primarily influenced by higher flock diversity and the presence of other non-woodpecker bark-foragers, the latter also playing a key role in enhancing their foraging success.
Monitoring is essential in conservation biology for assessing a species' population status and development. Many broad-scale programs rely on citizen science approaches but surveying rare or elusive species often requires specific training for volunteers. The Lesser Spotted Woodpecker Dryobates minor is an indicator of healthy forest ecosystems, particularly structurally rich deciduous and riparian forests. The species is difficult to observe due to its elusive behaviour, making reliable information about population status and habitat requirements scarce. Recognizing this critical data gap, a citizen science project was initiated in Hesse and Bavaria, Central and Southern Germany. The project, integrated into the national monitoring of rare breeding birds, trained volunteers to systematically map this species. Monitoring was conducted from 2021 to 2024 along 187 monitoring transects using playbacks to lure woodpeckers and the NaturaList app to record observations. Additionally, habitat data, such as the number of dead trees, proximity to water bodies and habitat type, were collected. Cavity cameras were used to monitor active breeding cavities. Lesser Spotted Woodpeckers were detected during 323 of 1012 surveys (32%), with detection probability peaking in March. The prior bird knowledge of the citizen scientists positively influenced detection probability. Species occurrence probability was highest in deciduous, riparian, and mixed forests characterized by large amounts of standing dead trees. Nest survival was 74%, with 1.8 fledglings per brood on average. Predators included Great Spotted Woodpeckers Dendrocopos major, and Garden Dormice Eliomys quercinus. Nest survival increased with the number of standing dead trees in the vicinity of breeding cavities. These findings emphasize the importance of deciduous forests and standing deadwood in supporting the species' occurrence and nest survival and highlights the value of citizen science as powerful tool for generating large-scale data, enabling more effective long-term monitoring of elusive species.
We present an overview of the past, present, and future of woodpecker research in the northeast Argentina, particularly in the diverse and threatened Atlantic Forest. Fifteen woodpecker species have been recorded in northeast Argentina. The majority, i.e. nine, of these woodpeckers are associated with the Atlantic Forest. As northeast Argentina maintains relatively large areas of this biome, globally important populations of these species occur here. Northeast Argentina maintains two old-growth Atlantic Forest sites that have been reference sites in comparative studies. Scientific collecting between 1949 and 1961 revealed the early distributions of rare woodpeckers in northeast Argentina. Research into the nesting ecology of cavity nesters including woodpeckers has been under way in northeast Argentina since 2003. Our research since 2008 has advanced the knowledge on roosting, nesting, and foraging ecology, and home range patterns, of Atlantic Forest woodpeckers, particularly of the globally threatened Helmeted Woodpecker Celeus galeatus. Our research points to the peculiar roosting ecology of Helmeted Woodpecker in decay-formed cavities as the key to its scarcity. Plumage convergence between the three largest Atlantic Forest woodpeckers may be driven by intraspecific (rather than interspecific) competition, and by Batesian mimicry in predator avoidance. Our current research addresses regional variations in densities and the composition of Atlantic Forest woodpecker species communities, and continent wide patterns in plumage and voice convergence. Regarding open questions, three of the northeast Argentina woodpeckers are typically seen in small groups while little is known about their reproductive systems. One species, Campo Flicker Colaptes campestris, has a contact zone in northeast between two subspecies, regarded as two species by some. Despite advances in recent years, there remains much research to be done into various aspects of woodpecker biology in the Atlantic Forest.
We investigated variation in home range size of the White-backed Woodpecker Dendrocopos leucotos, a species dependent on old-growth structures, in Central European forests varying in management intensity. Specifically, we used data from woodpeckers radio-tracked between 2016 and 2019 to test predictions of three hypotheses proposed to explain variation in home range size. Mean ( +/- SD) 95% home range size calculated with fixed kernel density estimation was 22 +/- 11 ha (N = 27) in the breeding season (approximate to April and May) and 47 +/- 27 ha (N = 28) in the post-breeding season (approximate to June and July). Home ranges of neighboring individuals overlapped neither in the breeding season nor in the post-breeding season, suggesting territoriality in both seasons. The resource distribution and intraspecific competition hypotheses were supported during the breeding season, whereas neither hypothesis explained post-breeding home range size. Breeding home range size decreased with both increasing forest area in the landscape and increasing proportion of resource-rich habitat (snag volume and trees with dead branches), the latter being particularly relevant when forest area was low. Moreover, breeding home range size decreased with increasing population density when the proportion of resource-rich habitat was high. The mechanisms determining breeding home range size thus varied with habitat quality in the landscape. In regions with low forest area and presumably generally low habitat quality, home range size appeared to be influenced by the distribution of resources. By contrast, in regions with high resource abundance and high population density, home range size seemed to be regulated by intraspecific competition. To improve habitat quality, deadwood and old trees should ideally be clumped within stands with little or no forest management. These resource-rich forests should constitute a high proportion of areas at least the size of a breeding home range and are particularly important in little-forested regions.
The Great Slaty Woodpecker Mulleripicus pulverulentus (GSWO), one of the world's largest, occurs in mature broadleaved forests of south- and southeast Asia. Habitat loss, logging, and timber extraction has caused a drastic population decline, due to which it is listed 'vulnerable' by IUCN. Despite its threatened status, basic knowledge about its breeding biology is deficient. We studied the nesting ecology of the GSWO in the Himalayan foothill Sal Shorea robusta dominated dipterocarp forests of Uttarakhand, northwest India over four years (2016-2019). We searched for active GSWO nests and documented various aspects of nesting from cavity excavation to fledging. Data were collected using direct observations by observers, as well as by video footage of active nests by cavity cameras and time-lapse cameras. We observed 9 nesting instances from 5 nesting cavities. All cavities were excavated in live Sal trees of DBH 53-98 cm (mean 73.4 cm). Nest excavation took a minimum of 9 days. Clutch size was 4, wherein one egg was laid per day over 4 successive days. Incubation period was 12-13 days. The number of chicks successfully fledged was generally 2 (range 1-3). Fledging duration was 5-6 weeks. Cooperative breeding was confirmed at 6 out of 9 nests, with 1-3 regular helpers (accompanied by 1-2 additional individuals) assisting the active pair in care of the young. Care duties were primarily shared between male and female adults, with minor/passive contribution by helpers. We documented instances of reuse of nest cavities across years by GSWO. We recorded predation on GSWO chicks by Bengal Monitor Varanus bengalensis lizards and Yellow-throated Marten Martes flavigula. Breeding success was 67%. Information generated during our study about the breeding ecology of the GSWO contributes towards a better understanding of the species and will aid to guide conservation actions targeted at this threatened woodpecker.
Remote sensing approaches can be used to describe forest characteristics that are important for avian conservation and management. Lidar is one such technology that can be used to describe forest structural characteristics that could influence woodpecker behavior, intra-and inter-specific interactions, and woodpecker demography. Given the sensitivity of woodpeckers to forest structure, we sought to assess how lidar has been incorporated into studies to improve understanding of woodpecker ecology. We conducted a literature review of articles that addressed lidar applications for studies of woodpecker species. Twenty-four studies included lidar in their projects addressing woodpecker ecology. There were 13 species represented within these studies, with 46% of the studies focused on a single federally listed species in the United States (the Red-cockaded Woodpecker Leuconotopicus borealis). Additionally, most studies focused upon ecological patterns related to distribution or space use, with a small number of studies focused on survival, reproduction, or dispersal. Almost all of the studies utilized airborne lidar data that were limited in spatial extent. The majority of studies were conducted in the United States, with only 8% studies occurring in Europe and no studies using lidar to study woodpecker ecology in the tropics. The globally available lidar data from the Global Ecosystem Dynamics Investigation (GEDI) instrument has been used to better understand aspects of carbon storage, ecosystem processes, habitat quality and biodiversity. The use of GEDI data and other global remote sensing products in conjunction with citizen science databases (e.g. eBird) and other sources of woodpecker data holds great promise for understanding large scale patterns of distribution. Incorporation of global forest structural data in studies of woodpecker ecology will likely help guide forest management activities that will benefit individual woodpecker species and the species that rely on them.
Intraspecific variation in nest size received considerable attention in the last two decades. A number of studies of small passerines found that nests built at lower ambient temperatures were larger than those built at higher temperatures. As larger nests, although costly, provide a better thermal environment for eggs and small nestlings, this has been interpreted as adaptive phenotypic plasticity. Yet, a comparable number of studies failed to confirm the relationship between temperature and nest size. We used data from a nest box population of Great Tits Parus major breeding in central Poland to test the possible effect of temperature on nest size built by females with multiple nests measured during a 3-year study. Using the sliding window approach, we identified the exact time window for which the given weather variable best explained the variation in the nest trait, in addition to that already explained by study year, clutch type (first or second) and female identity. For each nest trait and weather variable, we tested all possible time windows over a 30-day period prior to the first egg laying date (FED). We found that for the studied Great Tit population time windows of sensitivity of nest traits to temperature opened 19-24 days before FED and closed 6-15 days before FED. Maximum daily temperature was consistently a better predictor of nest size characteristics than either minimum daily temperature or mean daily temperature. For precipitation, the only significant sensitivity window opened 27 days before FED and closed 3 days before FED. Thus, temperature sensitivity time windows opened 5-10 days before the start of nest building and lasted no longer than halfway through the building period. Temperature effects were only detectable after accounting for the strong effects of female identity on nest size. The failure to observe temperature effects on nest size in some previous studies may be explained by considering temperatures during nest building rather than some time earlier, or by ignoring persistent female effects on nest size in the analyses.
In recent years, temperature data loggers have been used to collect breeding details including the duration of incubation breaks, detect the exact start of incubation, and record unsuccessful breeding in various types of bird nests. Nevertheless, the majority of conventional techniques are inapplicable in subterranean settings. This study presents the results of using a temperature data logger to monitor breeding phases and the transitions between them in the natural nest holes of the Common Kingfisher Alcedo atthis. The first sensor was placed inside an occupied nest chamber (during egg laying or incubation) beside the clutch, while the second sensor was placed in a reference hole near the nest at the same depth and height as the occupied nest hole. The temperature inside the nest chamber and the reference hole was measured continuously at one-minute intervals. Measurements were taken during various time periods, from egg laying/incubation to the successful fledging of chicks or their death. The temperature curves clearly indicate the laying of the eggs, the start of incubation, successful fledging, or the death of chicks in the nest chamber, and even other fine details such as diurnal fluctuations or levels of thermal stability. It was not always possible to determine exactly when the chicks hatched from the temperature data, as incubated eggs and freshly hatched chicks have similar temperature demands and receive similar heat from the brooding parent.
Inter-specific variation in trends of breeding phenology is well documented across cavity nesting passerines. However, general conclusions about the consistency of phenological shifts across closely related open nesting species are yet to be achieved. We used ringing data from 1960 to 2015 during the nesting season of three Acrocephalus species breeding in syntopy at a single fishpond area, "Bohdane & ccaron;sko" in the Czech Republic, to test whether long-term trends in the timing of the fledging period coincide among Common Reed A. scirpaceus, Marsh A. palustris, and Sedge A. schoenobaenus Warblers. Using logistic regression, we showed that trends in the fledging period were not fully consistent among the three closely related reed warblers. While the middle phases of the fledging period advanced in all species, the early phases were delayed in A. scirpaceus and A. schoenobaenus. The fledging periods became shorter in all species. The variation observed among these species makes it less likely that a single factor, such as climate warming, is the sole culprit of phenological changes. We suggest that interspecific competition and habitat change may have constrained Acrocephalus warblers from adjusting breeding times to increasing spring temperatures.
Close to 18% of the global avifauna require tree cavities for breeding and roosting. Cavities are therefore a critical resource for birds, and an understanding of its dynamics is vital to safeguard populations of cavity-users vis-& agrave;-vis forest management practices. Only a small proportion of trees in an ecosystem host this resource, and the likelihood of cavity presence on a tree may depend on how suitable its wood is for cavity formation, particularly through excavation by birds such as woodpeckers. Such understanding of which trees are more likely to host cavities than others is still lacking in the global tropics. To develop a baseline understanding of cavity resource dynamics in the Indian tropics, we estimated cavity abundance in a dry deciduous forest ecosystem in the northernmost Western Ghats, India, and investigated the ecological correlates of cavity occurrence. We recorded cavities only on trees with girth (GBH) greater than 80 cm, and limited our analyses to such trees. We found that 6.4% of 843 trees harboured cavities, and that 48% of all cavities were excavated. The study area contained a mean of 5.4 (95%CI 3.50-7.50) cavity trees, and 10.3 cavities (95%CI 8.60-12.20) per hectare. Species like Indian Rosewood Dalbergia latifolia and Teak Tectona grandis that are moderately hard-wooded were more likely to harbour cavities than the especially hard-wooded Terminalia crenulata, or soft-wooded species. We also found that trees with larger girth hosted cavities more often than smaller trees, with the relationship particularly strong in Teak. Our study suggests that prioritizing the preservation of large trees and cavity-associated tree species can aid in safeguarding cavities as a resource in such landscapes.
